SE1500503A1

SE1500503A1 - A three-dimensional imaging apparatus having a color mixing channel

Info

Publication number: SE1500503A1
Application number: SE1500503A
Authority: SE
Inventors: Moosberg Mats
Original assignee: Magicfirm Europe Ab
Priority date: 2015-12-10
Filing date: 2015-12-10
Publication date: 2017-06-11
Also published as: WO2017099645A1

Abstract

The present invention relates to a three-dimensional imaging apparatus for modeling a colored three-dimensional object on a layer-by-layer basis in accordance with a computer aided design (CAD) image of the object. The apparatus includes a printhead unit comprising a melting chamber; a primary feeding channel arranged between a supply of primary modeling material in solid state, preferably in filament form, and the melting chamber; driving means to drive and regulate the flow of the primary modeling material through the primary feeding channel toward the melting chamber; secondary feeding channels each of which is arranged between a supply of colorant material in solid state, preferably in filament form, and a color mixing channel in connection with the melting chamber; driving means to drive and regulate the flow of the solid colorant materials in accordance with a predetermined computer generated coloring pattern to the color mixing channel; heating means arranged adjacent to the color mixing channel and the melting chamber for supplying heat energy inside the color mixing channel and the melting chamber for converting the primary modeling material and the colorant materials therein from a solid state to a flowable fluid state to obtain a colored modeling material; a dispensing nozzle through which the colored modeling material in flowable fluid state is conveyed from the melting chamber to an object supporting platform positioned at a predetermined distance from the dispensing nozzle and motion devices coupled to said platform and said nozzle for moving said nozzle and said platform relative to one another in a plane defined by first and second directions and in a third direction orthogonal to said plane to deposit said flowable fluid material into a three-dimensional object.

Description

Field of the invention "fire present invention reiates to a cornputencoiitroiied ohjectnnodeiiiig :tpparatus fordepositing crïiiored ohjeets oii a iayer-hyaiztyfer hasis rrndei* the controi of a dataprocessing systeni.

Background of the invention Vifitii the increased use otiComprrter .Åided Design (CAD) soiid rnodeiirig systerns arieW frontier of manufacturing technoiogjv has emerged that enahies transiation of theQÉAD output data into a. tiireediniensionai (Ehiš) physicai ohject. 'ihis teciiiioiogyf iseornnioniy' referreri to as soiid tireeïftirrrt :fahri zatifoii (SF) or iayer rrtztniititeturiiig,vvhich entaiis huiiriing an object on a. iayer-hy'-iay'ei“ and pointáhy-poiiit hasis.

A crinirrierciaiiy atfaiiahie syfsteiri, *fused titan/rent. tiahricaftioii (FFF), rrses a heateririozzie to extrude a riiehed rnateiiai such as a piastic vifire. The starting material is inthe form of a fiiament hertig strppiied front a spooi, The fiianient is introduced into atiovv passage of the riozzie and is driven to inove iihe a piston inside this fiowpassage. 'ifhe tirorit end. near the nozzie tip, of this piston heateri to heeorne nieited;the rear end or soiid poitiori of this piston ptishes tiie rneited portion forvtfatrd to eXitthrough the riozzie tip. The nozzie is transiated trnder the coiitroi of a oornptitersystem in accordance vvith prevfiousiyf generated Cifiiš data. siiced iirto constituentiayers. 'The fFfFF teciiniqiie ttfas tiirst discioseri in ilS. ifat. Nio. 5,i2i,329 (i992),entitied "Apparatns and Method for Creating Tiireedširiieiisionai Ghjectsf' issued toS. S. Crtrrnp. The primary appiications of this techiiique have heen theifahrtication ofprototyfpes arid the creation of positive forrns to he trtiiized ininvestment cztsting processes. The users of the FF? teciinoiogftf have heretofore heeneoncerneri pzrirnztriiy vvitit tiie riirnensiontti accuracyf aiid siirface *tinisii of the *fin aipart. iiittie attention has heen paid to the forrnation ofa coior pattern on the surface orinside the hody of the iinai part.

Ariother tiased fiiarnent fahricatiori apparatus is disciosed in US patent No 6,ilZ9,S"/2entitied °°Cïompiitei~ controiied ohjecttfhuiiriing process and apparaftus for depositingeoioartiri rïihjects on a. iayenhy-iajwer hasis uiider the eontroi of a data processingsystern” isstied to Justin .iang .According to this patent, a tiiret-ndiirierisioiiai printingapparatus includes a supply of ﬁlament material; a ﬁlament-feeding devicecomprising one fiiarnent feeding channei and drive nreans such as motors to drive andireguiate the tion' of the fiiarrtent in the 'feeding ciiairnei; a dispensing nozzie havirig ation! passage crïirriiritriiicating vvitii this feediiig channei to receive tiie iiiarnent.tiieieiiorii., heating means for converting a ieading pcirtion of the tiianieiit to atiotvahie thiid state, and a discharge oritice to dispense the ihiid tiierethrongh. Theapparatus tiirtiier iiiciudes an ohjecesupportiirg platform in eiose, xfvorkiiig proxiniity to the diseharge orifi ee to receive the tiuid discharged therefrorn; and motion deviceseoupted to the piationn and the nozzie for moving the nozzie and the piatforinreiative to one anotiier in an XJY piane and in a tiiird direetioii (Z direction)orthogoriai to the X-Y piane to deposit the fiuid into a titreedimensionai ohj eeti "the apparattns iiirtiiei" ineindes a mnithehanirei eoioraritdiijeeting rnodnie eoinprisingan injeetiiig chanriei in ítïirïtvtf eotrirriuiiicatioii tvithi the ïtiovi' passage of the nozzie, areservoii' for a eoiorrtrit in fiovtf cornrniuriieation vvfith tiie injeeting channel, and vaivenieans in control reiatiori to tiie inieeting ehannei to reguiate the tiotv of the eoioraiittiierefitoiti; the injecting ohannei direeting the eoiorairt to inix vvith a. ieadiiig portion:of the tïiiarrient material ftir' *foriniing a eoiriraiihcoiitaining tittirii.

A riraivifhaek of sueh an appatratitis is tiiat the eoioiaiitdiiiectiiig ehaniieis iizrtfe to heioeated in the irn nrediate 'tficinityf of the diseharge orifice in order to permit a fastehangeover from one eoior to anotiier. if a eoiorant is introduced tvay npstrearn frornthe diseharge oriiiee, then it vvih tahe some time for a finid containing this ooiorant tohe eompieteiy' diseharged., 'this tviii tieiay the step of sitøitehing over to airothei* eoior.and pioiorig the transition period; :of time dnririg itthieii rriixiiig of coiorants takespiaee, in such a designi, a ehange-ovfer from one eoiotr to another tviii not he easiiyaeeoiiipiished and vviii take an exeessitfeijf iorig time to complete, aiiotviriguridesirahie rnixiirg of eoiorants to oeenr inside the ehannei before being disohargedrtirotn the oritice.

There is stiiiii a need for* a piintiiead strnetiire that eiiahies higher coior resohitirin in .athree-dirneiisionai ohjeet. Éšnrnntarjv' of the intention The *foregriing and other prohierris are oifercoirie aiid the ohjeets of the iiiventiori arereatiizert hy using an apparatios for :fahrieating a eriiozrerïi tiireefdirriiensioniai rihject: inaceordance xtfitii a ííAtlhgent-:rated image of the ohject and under tiie eontroi of acomputer, fås a ítiirst ernhoriirnent of the present inveritirin a tiiree-riirnensionzti intaging apparatnsfor rnrideiiiig a eoiored threddirnensionai object on a iatfeinhydafyer' ttasis inaeeordanee With a computer aided design (CAD) image of the ohject. The apparatusinoiudes a printhead unit comprising a rneiting eitamher; a primary' feediiig channeiarrariged ihetvtfeen a snppiy of primary ttiodeiing rnatierizti in stïtiid state? preíferahiy intïiiarnent forrn, and the irieitirig charnher; driving rïnearis to drive aiid reguiate the 'tiirivtfof the tarirnaiay iiiodeiiiig materiai through the printaify feeding channel totvard themeiting eharnher, The .apparatus further ineiudes secondary feeding channeis eaeii ofvvhieh is ananged hettveen a. stippiy' of eoiorant rnateriai in soiid state, preferahiy intiianient tiorni, and a cotor rnixiiig ehanznei arranged in eoniierttioii vvitii the rneitingcharnher; driving rnearis to drive and iegiuiate the tiirivv' of the soiid eoiorant materiaisin aeeordanee With a predeteriiiiiied computer generated cotoring pattern to the eoiormixiiig ehanrrei in itøhieh the ooiorant inateriais are meited together to ohtain a desired color. lås a specific color is ohtained, the rnelted colorant materials are coriveyed tothe ineltiiig chainher in ttfhieh they are inixed togetlter ytfith the modeling rnaterialtherein. The color mixing channel is arranged in connection yyitli the meltin gchamber. 'lille printhezttl iinit further includes lieatiiig iiieans arraitged adj acent to theoolfoi* rnixintg clrainnel, and the melting clianihei* for supplying heztt energy' iriside tliecolor rnixing chanriel anid the rnelting cliarriher 'for crnrvertiiig the prirriarfyf rnodelirrgmaterial and the colorant rnaterials therein front a solid state to a tloirfahle lluid stateto ohtain a colored inodeling material, "lfhe printhead unit :ftirtlter iiicludes adispensirtg iiozzle through vvliicli tlie colorerl rnorlelintg rnateii al in ïflrwrahle lluidstate is coinveyfed from the rnelting cliaiirher to an ohj ect supportiri g platfornipositioned at a predeteriitined distarree front the dispensing nozzle and motiondevices coupled to said platform and said nozzle for moving said nozzle and saidplatform relative to one another in a plane defined by first and second directions andin a third direction orthogonal to said plane to deposit said ﬂowable ﬂuid materialinto a three-dimensional obj ect.

The pirimary' modeling material may he eomprised of, hut is not limited to, one ormore of the folloyviiig iiiaterials including yarious ii/aaes, therrnoplastic polymers,tlierrnoset polymers, rnetallio alloys, glasses, ceraniics, and corrihinatttionts tlrezreritf. 'lfliematerial may also include coniliinations containirig dissirnilar materials added toimpart a desired electrical, structural, or other lurietional characteristic to theiiiaterial, lloytfeyer, the primary modeling material preferahly' coinprises an orgarticpolyrner vvitlr a reztsoriahlyf lott' srïrífteriing or rnel ting point, e. gt, aoryflonitrile-liutadienostyfrerie (tällä) or Polylactic acid (PLA). Preferably, the primary modelingmaterial is made of ABS or PLA material Without pigment additives to form acolorless transparent ground into Which the colorant materials can be mixed insidethe melting chamber. "flie colorant mztterial iiiay he a pigment or color concentïrate (cominonly used incoloriiig oïfplastirïsl) pirefeitahltyf in iilaineiit forrn. lligh concentirattte pigment rnatezrialallows qurick color changes. iådyrantagerituslyt, a first colorant filament is made of aCyan pigment, a second colorant lilanieiit is made of a hflïagenta pigment, a thirdcolorant filament is made of a Yellow pigment and a fourtlt pigment filament is made:of a Blaolt pigment in order to ohtairi a criloi" scztle in accorrlan ce *with ChflYK, colorsyfstems. ln a preferred ernhodirnerit of the riresent irivetntion, a ririnthead str“uctur“e includesfour different secondary feeding channels each of ytfhicli correspondirig to a specificcolorant material in filament form. 'lfhe colorant material filaineiits feed front theirsupplies (e, g. ïtitlament, spriolsf) tliroiigli upper inlet apertuzres of their* crirrespondingsecondary' feediiig chanriels, to the conveyerl hy crirresponding driving rneans thirorrghsaid charinels trivvard the color rriixin g channel in ißvhich they are rnelted anal tfnixedtogether to a specific color in aceordance With a predeterrniried coloring pattern.

An example of drfitfing means comprises a pluralitfyf of drive rollers drivensimultarteously hy a stepper motor. A plurality' of idler rollers located opposite to drive rolters ntay vvork tttgetiier tlierettfitit te grip the filatrierit therebetttfeert and toadvance it throughi a eorrespondiiig secondary' feediiig chatmet toward the notorrnixin g ehartnel.

The melting ehamher is dispesed in ctose proxiittity' te the primary tilantettt feedingeltannel and to the eoter mixing channet. The melting ehamher has a flow passagecorrirrtutiiealtlittg vvith the eohtr rrtixirig ehatntei threegtt tott/et* apertiires of tlteeliarnhet? to reeeirfe the filarnent rnateriats therefretïti. lefeatšsng means (än the form ef aresistance heating tape er sleeve) is pesitioned arround the tetver portion of theiitehing eharniber fer snpplying lieat energy inside the melting eltamber for convertinga leading pttrtion of' the rriodeling tilztrnent rrtatezrial and a teadittg portions of thecotorant ﬁlament rnaterials to a tilottfable flešd state. The sehd (surimetted) portšrtrr efthe filaments iriside the feeding ehlannets aets liíke pistens te drive the mehed liquidinto the melting eltamber ttfherein the modelntg inatettial and the eotoraitt materialsare rnixed to ohtairt a cttlozreti íftuid in .aeeorrtaitce ttfitltt a predgeteirriined eohai* pattern."The rtrive rnotors ean be coittrolled te iregutztte the .advanlcinsg irate ef the ctïtlorztntt'titarnertts in the secttridary' feeding ehanriets st: tfiat the svolentettrie dispensirtg rate efthe flnid ean he elosety controlled in aecei'dance vvith the color pattern.

Brief eleseriptien ef the elratt/higs Figl is a sehernatic cross seetioii view ef an apparatus in aeeordanee vvitli the presentinvention Beseription ef a preferred emhodimertt fås schematically shown in fig, l, a preferred einhodiment of the present intfetitioninctudes a printheatl rtnit having a rittzale ihttack iretfeirathtsyf retade ef a rnateriztl Witha thermal conductivity greater than 25 W/(m-K), such as, for example, brass orsimilar metallic alloys. The nozzle block l encloses a melting chamber Which canbe heated to a temperature sufﬁciently high for the ﬁlaments to liquify. The melting is surrounded by heater elements and a temperature sensor thatregulate the temperature inside the melting chamber to a temperature ofapproximately 200°C to 240°C. The printhead unit is further provided With a plurality __ __ are arranged in connection With the secondary feedingc annels to drive t e 1 aments toward the color mixing channe An example ofdrive means comprises a plurality of drive rollers connected to one another by asuitable belt or chain drive and driven simultaneously by a stepper motor and a drivebelt or chain. A plurality of idler rollers located opposite to drive rollers may Work together therewith to grip the ﬁlament therebetween and to advance it toward thecolor mixing channel __ and therefrom to the melting chamber The disperisirie nozzie ﬁ is disposed in ciose tiroxirnity to the tiiiarrient 'feedirigehanneis _ __ The nozzie _ f is shotvri to he intinratety connected to nreitingcitainher 2 and the fiiainenhfeedrng ehanneis __ __ __ The nozzie has a fiow passagecorrrrriiiirieattiiiig vvith the :feeding ch annei tirrougir a it3vver apezrttiie of the charnher” toreceive the 'fiiarnent inateriai tiierefiorri. iieater eienieirtsresistance heating t ie or sieeve) are positioned arrourid the tower portion oftheiiiehing charnhe tor converting a ieadirrg portion of the tiiarnent niateriai to atiotrfahie fi uid state, "fire soiid (rrn-rrieiteri) pozrtioii of the *fiiarrieiits insirie the ífeediinigchanneis ct iihe pistons to drive tire rneited iiqtiid for di spensing through adisciraige orrfree. The drive rnotor can he controiied to ifegniate theadvttneing rate of the fiiarnent in the feeding cirannei _ that the voinnietricdispensiiig rate of the thiiri can he eioseiy' coirtrotied.

A phrraiity' of coiorant feeding ehanireis are disposed in the tficinity of the rneitingcharifiher Gniy three of the icfhanneis are shottfii, as an exarnpie, in Pig. i. As thecoiorant frtarrrerit is coirvtetfed inside the ooior rriixiiig channei, it is converted fionr asoiid state to a tiottfahie thrid state and is therehy rrrixed together in order to forrn aeoiored fhiid material vvhieh can he niixed tvith the prinrary inodeiirrg iiiateria_i___irt therrieiting eiiarrrher aiid theireriífter rieposited tirrougii the riispensirig irrizzie fšeferring agatin to Pig, i, the ohject piatforrri is ioeated in cirise, vtaoifkiiigtiroxirnity to the dispensing ririzzie. The upper surface of the piatforrn preferahiyr has afiat regiori sutﬁeieirtiy iarge to aceorniirodate the first fevv iayers of the depositedniateriai. The piattorrn and the nozzie are equipped tvith rneciiarricai drive rrtearis :fortriottfiiig the piatforrn reiatitze to the di speiisin g niozziie in tiiree ditrieirsiitïriis aiong theX4, Yi, .and Z-axes in a rectarigriiati* crioirdiiiate systern in a pierieteirriiiieri seqrieiieeand patterrr, and for dispiacirig the nozzie a predeteriïiiiiied incrernentai distancereiative to the piatforrn. This can he aecornpiished, for instance, hy aiiottfiiig thepiattforrir to he driven hy three iinear niotiorr detfiees, *vvhieii are porvered hy threestepper rrrritors to pirnfirie rriovernenits afioiig the *X-, Yë, and Z-riirectioiis, :respectitfeijy.Motor rrieans are preferaiiiy' hi gh resohitiori rreversihie stepper rnotors, aittiriitgh othertf/pes of drive niotors niay he nsed, irichidirig iiriear rnotors, servorrrotors,synchronous inotors, DC. rnotors, and fiiiid iiiotors. Mecitairicai drive rneansinciudirig iiiieati* motion rievices, rnotrirs, and gatntijtf type posititïiniiig stages are vveiihnovtfn in the att.

Z-axis rnoveiiierits are effected to dispiace the tiiatfotrn tveiative to the irozzie or todispiace the nozzie 'iieiative to the tiiatforrrn and, iience, reiatitfe to each iayerdeposited prior to the start of the forination of each stiecessitfe iayer. in one possihiearrangernent, the nozzie and other hardvvare attached to the nozzie rnasf he nioiintetiin a irnotvri 'fasiritïiii for rnotfetrieiit in the hX-Y piane, tvitir the piatíftïﬂrrri siipported forseparate iïiiotfernent toxvard and avvay fronr the nozzie aiong the Z-directioir.ßdternatitfeiyf, the piatforrn inav he sitpported tor inovenierit in the X-Y piane, *with tiie ntazzie metinted "Fei" separate iiiovetiieiit aiong the Zætireetion text/eid anti att/eytietii thep1atfeim. Anethet alternative is te iiatfe the tmovements in the X-Y piane aiidiii the Zæiiteetion ah to he eztrtieà out hy either the gxiattertti eitiy ei hy the iiozzieeniy. it itfiii he undeistoc-ci that meveineiit in the X» Y piztne neeá iiot the iimited temoifetnent: in tttthegonai direetiens, hut ttizty iiieitide nioveineht in tadiai, tahgentiai,atrctiate anti ether direetiotns in tiie X-Y piahe.

Claims

1.) A three-dimensional imaging apparatus for modeling a colored three-dimensional object on a layer-by-layer basis in accordance vvitli a computerziided (iesign (Czälš) irriage of strid object, comprising: a supply of primary modeling material in solid state;an object supporting platform; a printhead unit including a melting chamber; a primary feeding channelarranged between said supply of primary modeling material and said meltingchamber; drive means to drive and regulate the ﬂow of said primary modelingmaterial through said primary feeding channel toward said melting chamber; heating means arranged adjacent to said melting chamber for supplying heatenergy inside said melting chamber for converting said primary modelingmaterial therein from a solid state to a ﬂowable ﬂuid state; a dispensing nozzlefor conveying said ﬂowable ﬂuid material from said melting chamber to saidobject supporting platform; motion devices coupled to said platfonn and said nozzle for moving saidnozzle and said platform relative to one another in a plane defined by first andsecond directions and in a third direction orthogonal to said plane to depositsaid ﬂowable ﬂuid material into a three-dimensional object; characterized in that said apparatus further includessupplies of colorant material in filament fonn; secondary feeding channels arranged in said printhead unit between eachsupply of colorant material in solid state and a color mixing channel arrangedin connection with said melting chamber; drive means to drive and regulate the ﬂow of said solid colorant materials inaccordance with a predetermined coloring pattem to said color mixing channelin which said colorant materials is converted from a solid state to a ﬂowableﬂuid.

2.) A three-dimensional imaging apparatus as claimed inthat said printhead unit comprises four secondary feeding channels each ofwhich is coupled to one specific supply of colorant material.

3.) A three-dimensional imaging apparatus as claimed in any of claim 1 to claim characterized in that the modeling material consists of plastic material Withoutpigment additives.

4.) A three-dimensional imaging apparatus as claimed in any of claim 1 to claim characterized in that the modeling material consists of plastic material WithWhite pigment additives.

5.) A three-dimensional imaging apparatus as claimed in any of claim 1 to claim characterized in that the colorant material consists of plastic color concentrates.

6.) A three-dimensional imaging apparatus as claimed in any of claim 1 to claim characterized in that the colorant materials consist of cyan, magenta, yellowand black color concentrates in accordance With the CMYK color system.

7.) A three-dimensional imaging apparatus as claimed in any of claim 1 to claim characterized in that the secondary feeding channels communicate With themelting chamber through apertures that are smaller than the aperture of theprimary feeding channel.

8.) A three-dimensional imaging apparatus as claimed in any of claim 1 to claim characterized in that the secondary feeding channels communicate With themelting chamber through apertures that distribute the colorant materials at theoutline of the dispensing nozzle.